Editing Ellipse (section)

==== Optics ====
* In a material that is optically [[anisotropic]] ([[birefringent]]), the [[refractive index]] depends on the direction of the light. The dependency can be described by an [[index ellipsoid]]. (If the material is optically [[isotropic]], this ellipsoid is a sphere.)
* In lamp-[[laser pumping|pumped]] solid-state lasers, elliptical cylinder-shaped reflectors have been used to direct light from the pump lamp (coaxial with one ellipse focal axis) to the active medium rod (coaxial with the second focal axis).<ref>[http://www.rp-photonics.com/lamp_pumped_lasers.html Encyclopedia of Laser Physics and Technology - lamp-pumped lasers, arc lamps, flash lamps, high-power, Nd:YAG laser<!-- Bot generated title -->]</ref>
* In laser-plasma produced [[Extreme ultraviolet|EUV]] light sources used in microchip [[Extreme ultraviolet lithography|lithography]], EUV light is generated by plasma positioned in the primary focus of an ellipsoid mirror and is collected in the secondary focus at the input of the lithography machine.<ref>{{cite web |url=http://www.cymer.com/plasma_chamber_detail/ |title=Cymer - EUV Plasma Chamber Detail Category Home Page |access-date=2013-06-20 |url-status=dead |archive-url=https://web.archive.org/web/20130517100847/http://www.cymer.com/plasma_chamber_detail |archive-date=2013-05-17 }}</ref>